A 3GPP communication system often comprises numerous wireless networks (also interchangeably referred to herein as wireless domains), such as Long Term Evolution (LTE) networks, Universal Mobile Telecommunications System (UMTS) networks, Global System for Mobile Communications (GSM) networks, WiMax networks, etc (also referred to generally herein as 3GPP networks or 3GPP domains). Each 3GPP network includes one or more infrastructure devices, such as a Mobility Management Entity (MME) for instance, which provide connectivity, roaming, and other communication services to enable the communication of media to wireless devices (also interchangeably referred to herein as User Equipment (UE)). A wireless device is often associated with a designated wireless network. As used herein, the designated wireless network for the wireless device is termed a home wireless network (also interchangeably referred to herein as a home wireless domain, a home 3GPP wireless domain, and a home LTE wireless domain) to the wireless device. As mentioned above, a feature of the 3GPP communication system is roaming, which allows a wireless device to connect to wireless networks other than the home wireless network of the wireless device. As used herein, the wireless networks other than the home wireless network of the wireless device are termed as foreign wireless networks (also interchangeably referred to herein as foreign wireless domains, foreign 3GPP wireless domains, and foreign LTE wireless domains) to the wireless device.
As described in 3GPP standards, when a wireless device attaches (i.e., connects) to a foreign 3GPP wireless network, the foreign 3GPP wireless network attempts to authenticate and authorize the wireless device using a standard 3GPP authentication mechanism, which includes obtaining authentication credentials from the home 3GPP wireless network of the wireless device. To obtain such authentication credentials, the MME of the foreign wireless network contacts the Home Subscriber Servers (HSS) of the home wireless network through a standard 3GPP S6a interface.
In order to use the S6a interface, the foreign and home wireless networks must have a roaming agreement. However, such a roaming agreement requirement creates a scalability problem for the 3GPP communication system as the number of 3GPP domains in the system increases since roaming agreements between all of the networks would be required to achieve a fully meshed nation-wide network. Moreover, even in the presence of roaming agreements between wireless networks in the system, a communication link between two wireless networks may be broken or interrupted for various reasons, such as natural disasters. This would also prevent the foreign MME from obtaining the authentication credentials for the wireless device attempting to attach to the foreign 3GPP network.
Therefore, what is needed is a method for authenticating a wireless device to a foreign 3GPP network when the standard 3GPP authentication mechanism fails or is otherwise unavailable.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative other elements to help improve understanding of various embodiments. In addition, the description and drawings do not necessarily require the order illustrated. It will be further appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required.
Apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the various embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Thus, it will be appreciated that for simplicity and clarity of illustration, common and well-understood elements that are useful or necessary in a commercially feasible embodiment may not be depicted in order to facilitate a less obstructed view of these various embodiments.